web3-proxy/web3_proxy/src/frontend/users.rs

// So the API needs to show for any given user:
// - show balance in USD
// - show deposits history (currency, amounts, transaction id)
// - show number of requests used (so we can calculate average spending over a month, burn rate for a user etc, something like "Your balance will be depleted in xx days)
// - the email address of a user if he opted in to get contacted via email
// - all the monitoring and stats but that will come from someplace else if I understand corectly?
// I wonder how we handle payment
// probably have to do manual withdrawals

use axum::{
    response::{IntoResponse, Response},
    Extension, Json,
};
use axum_client_ip::ClientIp;
use entities::user;
use ethers::{prelude::Address, types::Bytes};
use reqwest::StatusCode;
use sea_orm::ActiveModelTrait;
use serde::Deserialize;
use std::sync::Arc;

use crate::app::Web3ProxyApp;

use super::{rate_limit::RateLimitResult, errors::anyhow_error_into_response};

pub async fn create_user(
    // this argument tells axum to parse the request body
    // as JSON into a `CreateUser` type
    Json(payload): Json<CreateUser>,
    Extension(app): Extension<Arc<Web3ProxyApp>>,
    ClientIp(ip): ClientIp,
) -> Response {
    let _ip = match app.rate_limit_by_ip(ip).await {
        Ok(x) => match x.try_into_response().await {
            Ok(RateLimitResult::AllowedIp(x)) => x,
            Err(err_response) => return err_response,
            _ => unimplemented!(),
        },
        Err(err) => return anyhow_error_into_response(None, None, err).into_response(),
    };

    // TODO: check invite_code against the app's config or database
    if payload.invite_code != "llam4n0des!" {
        todo!("proper error message")
    }

    // TODO: dont unwrap. proper error
    let signature: [u8; 65] = payload.signature.as_ref().try_into().unwrap();

    // TODO: calculate the expected message for the current user. include domain and a nonce. let timestamp be automatic
    let message: siwe::Message = "abc123".parse().unwrap();
    if let Err(e) = message.verify(signature, None, None, None) {
        // message cannot be correctly authenticated
        todo!("proper error message: {}", e)
    }

    let user = user::ActiveModel {
        address: sea_orm::Set(payload.address.to_fixed_bytes().into()),
        email: sea_orm::Set(payload.email),
        ..Default::default()
    };

    let db = app.db_conn.as_ref().unwrap();

    // TODO: proper error message
    let user = user.insert(db).await.unwrap();

    // TODO: do not expose user ids
    (StatusCode::CREATED, Json(user)).into_response()
}

// the input to our `create_user` handler
#[derive(Deserialize)]
pub struct CreateUser {
    address: Address,
    // TODO: make sure the email address is valid
    email: Option<String>,
    signature: Bytes,
    invite_code: String,
}